Drilling operators logically need as much information as possible about borehole and formation characteristics while drilling a borehole for safety and reserves calculations. If problems arise while drilling, minor interruptions may be expensive to overcome and, in some cases, pose a safety risk. Since current economic conditions provide little margin for error and cost, drilling operators have a strong incentive to fully understand downhole characteristics and avoid interruptions.
Downhole measurement tools, often referred to as measurement while drilling tools or logging while drilling tools, are used to collect data about downhole parameters in a borehole during drilling of the borehole. The collected data can be used to make various interpretations about conditions downhole and to adjust the drilling operation. The downhole measurement tools may be disposed at various points along the drill string used in drilling the borehole in order to collect data about downhole parameters at various points along the borehole.
The downhole measurement tool typically arrives at the drill site as a drill string part ready to be included in a drill string. For example, the downhole measurement tool may arrive at the drill site mounted on or inside a drill bit, which will become part of the drill string. Or, the downhole measurement tool may arrive in the form of a pipe joint to be included in the drill string. To conserve battery power, the downhole measurement tool, after configuration as a drill string part, may be in a sleep mode. Before the downhole measurement tool can be used, the downhole measurement tool would have to be switched from the sleep mode to the active mode. To save time, it is desirable that the downhole measurement tool can be switched from the sleep mode to the active mode without altering the ready-to-use configuration of the downhole measurement tool. For example, if the downhole measurement tool is already mounted on or inside a drill bit or otherwise attached to a drill string, it would be desirable that the downhole measurement tool can be switched from the sleep mode to the active mode without dismantling the downhole measurement tool from the drill bit or drill string.
The downhole measurement tool typically includes a storage device for storing the data collected in the borehole. The collected data can be sent to the surface while the downhole measurement tool is in the borehole. Alternatively, the collected data may be downloaded from the storage device when the downhole measurement tool is retrieved to the surface. To save time, it is desirable that the collected data can be downloaded from the downhole measurement tool without altering the ready-to-use configuration of the downhole measurement tool or dismantling the downhole measurement tool from the drill string.
U.S. Pat. No. 6,831,571 (Bartel) describes a method for transferring data from a logging tool to a surface computer that involves attaching a standalone data dump device to the logging tool after the logging tool has collected data about downhole parameters and is raised to the surface. The data dump device includes an enclosure inside of which is disposed a data dump memory and a processor. The data dump device also includes a connector to couple the processor to the memory and to attach the enclosure to the logging tool. The data dump device includes a transmitter/receiver circuit coupled to the processor, where the transmitter/receiver circuit allows communication between the data dump device and a surface computer. The data dump device is designed to be physically connected to the logging tool in order to download data from the logging tool.
In U.S. Pat. No. 6,831,571, where the ready-to-use configuration of the logging tool is such that the logging tool is mounted in a hard-to-reach area, e.g., inside a drill bit, it would be difficult or impossible to make a reliable physical connection between the data dump device and the logging tool.